Lighting systems are commonly used to illuminate public areas. Light sources of outdoor lighting systems are typically turned on in response to low ambient light conditions (e.g., after sunset) and turned off during high ambient light conditions (e.g., during daylight hours). Many outdoor lighting systems with automatic on-off control systems responsive to ambient light conditions include photoconductive cells photocells).
Known outdoor lighting fixtures with automatic on-off control include photocells sensitive to visible light. Such photocells cannot distinguish between ambient light and light produced by the lighting fixtures. In order to prevent the photocells from being influenced (e.g., triggered) by the light produced by the lighting fixtures, the photocells must be oriented (i.e., aimed) away from the light exiting the lighting fixtures. As a result, the photocells are often positioned in locations where they are subject to harmful conditions.
Lighting systems can also suffer from poor or suboptimal power factor correction (PFC). Poor PFC performance can lead to decreased component longevity. Poor PFC performance can also cause the expensive wasting of power as heat, along with the concomitant need to dispose of such heat.
Such conditions can be of particular concern when high-voltage power is used for lighting systems, such as solid state lighting devices, including those with LEDs. Accordingly, there is a need for improved lighting techniques.